That was slightly more painful than really necessary..
It's not as big as the first RC (well, the first RC is always a big one because it allows you put most of new things there and next RC is trying to stabilizing the kernel after new changes has been stopped) but it's always worthed to see the changelog (too bad, KernelNewbies hasn't been updated to reflect the latest changes on kernel 2.6.19. They give more human readable information rather than reading directly to the long-format changelog).
You can see some new information about RC2 in LWN. It has more detailed information about big interrupt handler prototype change and also initial merge of the developmental ext4 filesystem with a few enhancements.